Patch wireless test fixture

ABSTRACT

In general, a pressure rail having a top surface and a bottom surface and one or more pressure inlets to a pressure channel can be located within the pressure rail. The pressure channel can be drilled into the pressure rail. A plurality of patch depressions can be formed into a plurality of sealing surfaces on the top surface of the pressure rail upon which a patch is positioned. A plurality of antenna blocks is generally disposed upon the pressure rail, wherein each antenna block thereof includes at least two antennas. Two antennas can be connected to a respective antenna block among the plurality of antenna blocks utilizing a silicone adhesive. Each antenna block is respectively located on the pressure rail in order to provide wireless data indicative of pressure and temperature conditions associated with each patch among the plurality of patches.

TECHNICAL FIELD

Embodiments are generally related to sensing methods and systems.Embodiments are also related to pressure and temperature sensors.Embodiments are additionally related to surface acoustic wave (SAW)devices and sensors, and in particular to testing methods and systemsthereof.

BACKGROUND OF THE INVENTION

Various sensors are known in the pressure and temperature sensing arts.The ability to detect pressure and/or temperature is an advantage to anydevices which are under constant temperature and which can be severelyaffected by temperature conditions. An example of such a device is anautomobile tire, which of course, experiences variations in bothtemperature and pressure. Many different techniques have been proposedfor sensing the pressure and/or temperature in tires, and for deliveringthis information to the operator at a central location on the vehicle sothat he knows that a tire is at low or high air pressure.

Such sensors generally communicate with the vehicle so that the sensedpressure and/or temperature are displayed to the operator when thevehicle is moving, i.e. the wheel rotating relative to the body of thevehicle. Such devices are generally relatively complex and expensive oralternatively are not particularly robust.

Some tire pressure and/or temperature sensor systems incorporate asensor that is fixed to the body so no rotating electrical contactbetween the rotating wheel and the chassis is required. In this system,a sensor rod is deflected by contact with the tire sidewall when thesidewall of the tire is deformed as occurs when the tire pressure islow. This system provides an indication of low tire pressure but is notrobust. For example mud or other debris on the wheels may cause faultyreadings. Furthermore, this system provides an indication only when thetire pressure is reduced significantly as is necessary for significanttire bulge to occur. Clearly such a system simply cannot provide areading of actual tire pressure.

In another form of fixed sensor the height of the vehicle can bedetected and when the height is reduced, it is deemed tire pressure islow. However, if the tire in a rut or is parked on uneven ground, afaulty low-pressure reading is likely to be generated.

More complicated systems are capable of monitoring tire pressure. Forexample, some pressure sensor systems utilize a rotating encoder formedby a multi-polar ring of magnetic segments of different polarity thatare distributed circumferentially in a regular and alternating manner. Atransmitter coil coaxial with the ring and a fixed pickup (an inductioncoil system) is energized by alternating electrical current flowingthrough the transmitter coil to generate a magnetic field superimposedon the magnetic field created by the multi-polar ring generates a signalpicked up and delivers a signal relating the rotating characteristic ofthe wheel and thus, the state of the tire.

Some tire pressure systems also utilize a wheel system wherein eachsensor on each wheel is provided with a radio transmitter that transmitthe information on tire pressure, etc. from the wheel to a radioreceiver on the body of the vehicle and this transmitted signal isdecoded to provide information on tire pressure etc. and makes itavailable to the operator. Conventional wireless systems, however, arenot durable and are expensive to design and produce.

One type of sensor that has found wide use in pressure and temperaturesensing applications, such as, vehicle tires, is the Surface AcousticWave (SAW) sensors, which can be composed of a sense element on a baseand pressure transducer sensor diaphragm that is part of the cover. Fora SAW sensor to function properly, the sensor diaphragm should generallybe located in intimate contact with the sense element at all pressurelevels and temperatures.

To compensate for expansion in the packaging, the sense element andsensor diaphragm must be preloaded when they are assembled to shift theoutput frequency a known amount, which ensures contact at all times. Inconventional sensor designs, an interference fit between the cover andbase can maintain a preload until the cover and base are locked in placeby welding, soldering or other connecting means.

In order to properly configure a sensor, such as a SAW sensor, thesensing device must undergo rigorous testing to ensure that the devicewill work properly under a variety of temperature and pressureconditions. A system should be implemented in which to test overallfunctionality in an environment similar to the type that the sensor willultimately face. For example, a SAW sensor is ideally suited fur use insensing tire temperature and pressure conditions. The sensing devicemust be able to react to high and low temperatures (e.g., 100° C. to−40° C.), while also being able to react to varying pressure ranges(e.g., 0 psi to 150 psi). It therefore necessary to test the sensor toverify functionality over variations in temperature and pressure, andalso to ensure that the sensor external components (e.g., sensorhousing) can withstand these varied conditions.

Additionally, tests must be performed to ensure that sensor devicecomponents such as the housing will not be affected by RF frequenciesdue to the presence of wireless components, such as antennas. Thehousing and base of the sensor must also not be placed into a conditionin which an electrical short runs from the housing to the base, causinga frequency shift or error in the sensor measurements. A need thusexists for an improved method and system for properly testing sensordevices, such as SAW sensors. It is believed that providing configuringa proper patch system, particularly one involving wireless capabilities,will greatly enhance sensor testing, and thus provide for sensors thatare ultimately more efficient and sturdier than presently implementedsensors.

BRIEF SUMMARY OF THE INVENTION

The following summary of the invention is provided to facilitate anunderstanding of some of the innovative features unique to the presentinvention and is not intended to be a full description. A fullappreciation of the various aspects of the invention can be gained bytaking the entire specification, claims, drawings, and abstract as awhole.

It is, therefore, one aspect of the present invention to provide animproved sensor testing method and system.

It is another aspect of the present invention to provide for a sensortesting method and system, which can be utilized to rest theeffectiveness of surface acoustic wave (SAW) sensor devices.

The aforementioned aspects of the invention and other objectives andadvantages can now be achieved as described herein. A sensor testingsystem and method are disclosed herein. In general, a pressure railhaving a top surface and a bottom surface and one or more pressureinlets to a pressure channel can be located within the pressure rail.The pressure channel can be drilled into the pressure rail. A pluralityof patch depressions can be formed into a plurality of sealing surfaceson the top surface of the pressure rail upon which a patch ispositioned. A plurality of antenna blocks is generally disposed upon thepressure rail, wherein each antenna block thereof includes at least twoantennas. Two antennas can be connected to a respective antenna blockamong the plurality of antenna blocks utilizing a silicone adhesive.Each antenna block is respectively located on the pressure rail in orderto provide wireless data indicative of pressure and temperatureconditions associated with each patch among the plurality of patches.

Additionally, a plurality of BNC connectors can be respectivelyconnected to the plurality of antenna blocks, wherein each BNC connectorthereof is respectively connected to and protrudes from each antennablock thereof. Each sealing surface among the plurality of sealingsurfaces can be configured to contain a groove that retains a respectiveO-ring in place. The patch itself can comprise a SAW patch. Also, aplurality of cap screws can be provided for holding in place an antennablock among the plurality of antenna blocks and for sealing therespective O-ring against a respective antenna block among the pluralityof antenna blocks. The pressure rail therefore can generally function asa SAW tire pressure measurement patch wireless test rail. The SAW patchreacts to both temperatures and pressure while being interrogatedwireless as a fixed distance in order to collect test data indicative ofthe SAW patch.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, in which like reference numerals refer toidentical or functionally-similar elements throughout the separate viewsand which are incorporated in and form a part of the specification,further illustrate the present invention and, together with the detaileddescription of the invention, serve to explain the principles of thepresent invention.

FIG. 1 illustrates a top view of a wireless sensor testing system, whichcan be implemented in accordance with a preferred embodiment of thepresent invention;

FIG. 2 illustrates a side perspective view of the wireless sensortesting system depicted in FIG. 1, in accordance with a preferredembodiment of the present invention;

FIG. 3 illustrates a front view of the wireless sensor testing systemdepicted in FIGS. 1-2, in accordance with a preferred embodiment of thepresent invention;

FIG. 4 illustrates a right side view of the wireless sensor testingsystem depicted in FIGS. 1-3, in accordance with a preferred embodimentof the present invention; and

FIG. 6 illustrates top and side views of a sensor, which can be testedby the testing system depicted in FIGS. 1-4, in accordance with apreferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The particular values and configurations discussed in these non-limitingexamples can be varied and are cited merely to illustrate at least oneembodiment of the present invention and are not intended to limit thescope of the invention.

FIG. 1 illustrates a top view of a wireless sensor testing system 100,which can be implemented in accordance with a preferred embodiment ofthe present invention. FIG. 2 illustrates a side perspective view of thewireless sensor testing system 100 depicted in FIG. 1, in accordancewith a preferred embodiment of the present invention. FIG. 3 illustratesa front view of the wireless sensor testing system 100 depicted in FIGS.1-2, in accordance with a preferred embodiment of the present invention.FIG. 4 illustrates a right side view of the wireless sensor testingsystem 100 depicted in FIGS. 1-3, in accordance with a preferredembodiment of the present invention.

System 100 generally includes a pressure rail 122 upon which aredisposed a plurality of antenna blocks 102, 104, 106, 108, and 110.Pressure rail 122 includes a pressure inlet 124. Five individualdepressions can be cut into the top surface of pressure rail 122 forplacement and orientation of a SAW patch, such as, for example, SAWpatch 136. Note that SAW patch 136 can be formed from a material such asrubber. An example of one depression cut into the top surface ofpressure rail 122 is patch depression 134 depicted in FIG. 2. Pressureinlet 124 forms part of a pressure channel, which can be drilled throughthe center of pressure rail 122 to help pressurize a SAW button facethat can be molded into each SAW patch (e.g., SAW patch 136). Each ofthe five locations upon which antenna blocks 102, 104, 106, 108, and 110are located contains a dovetail groove milled into the sealing surfacethat holds a silicon O-Ring in place, while also assisting in retainingthe O-ring. AN example of such a dovetail groove is O-ring groove 132depicted in FIG. 2. Each O-ring helps to seal against the respectiveantenna block that is held in place with four cap screws. For example,antenna block 110 is held in place by cap screws 124, 126, 128 and 130.Each of the antenna blocks 102, 104, 106, 108, and 110 can be configuredto include two antennas mounted within respective antenna grooves, 140,142, 144, 146, and 148, wherein each of the antennas are held in placewith an adhesive, such as, for example, a silicone adhesive. Each of thetwo antennas can be wired to a respective BNC connector that protrudesfrom the top of each antenna block. For example, antenna block 110 isassociated with a BNC connector 120. Antenna blocks 102, 104, 106, 108,and 110 are respectively associated with BNC connectors 112, 114, 116,118, and 120.

FIG. 5 illustrates a block diagram of a system 500 for SAW testing, inaccordance with a preferred embodiment of the present invention. Notethat in FIGS. 1-5, similar or identical parts or elements are generallyindicated by identical reference numerals. Thus, according to system500, each BNC connector 112, 114, 116, 118, and 120 can be connected toa test system 502 that monitors and regulates temperature and pressureconditions. In general, system 500 can be adapted for use as a SAW tirepressure management patch wireless test rail, which includesapproximately five rubber patches that can be pressurized up to 150 psi,and which can also be heated up to approximately 135 degrees Celsius,while an embedded antenna interrogates a SAW patch, such as, forexample, SAW patch 136. System 500 allows the SAW patch to react both totemperature and pressure while being interrogated at a fixed distance inorder to help collect final test data.

FIG. 6 illustrates top and side views of a sensor 600, which can betested by the testing system 100 depicted in FIGS. 1-3, in accordancewith a preferred embodiment of the present invention. Sensor 600generally comprises a SAW button sensor or sensory assembly. Sensor 600includes a sensor base which is composed of base portions 620, 612 and624. Two pins 608 and 610 can be mounted and/or connected to the sensorbase. Such pins 608 and 610 can be located within areas 630 and 632 ofthe sensor base. Sensor 600 generally includes a sensor cover 606 whichcan be configured to include a dimple 602. Note that the particularshape and size of dimple 602 can vary, depending on particularapplications. The dimple 602 depicted in FIG. 6 is thus presented forillustrative purposes only and the size and shape thereof are notconsidered limiting features of the present invention.

A sensor element 628 can be located adjacent to or on base portion 612in a manner that that permits clearances to form between sensor cover606 and the sensor base composed of base portions 620, 612 and 624. Asensor diaphragm 603 can be incorporated into the sensor cover 606. Thecover 606 can be located the sensor base such that the dimple 602 is inintimate contact with the sensor element 628 at all pressure levels andtemperatures thereof.

It can be appreciated from FIG. 6, that instead of using an interferencefit between the cover and base, the components thereof can be designedto form a clearance or gap between the cover and base. Such a designdoes not rely on an interference between the two parts to maintainpreload, but instead can utilize welding, soldering or other connectingmeans to lock the components in position at the time the cover isassembled to the base.

The components can be designed such that even if the cover is at itssmallest inside dimension within the tolerance range and the base is atits largest outside dimension within the tolerance range there will beclearance between them when they are assembled together. Thus, aclearance should exist generally between the cover and base even if thecover is at its smallest dimension within the tolerance range and thebase is at its largest dimension within the tolerance range. The intentof such a feature is to produce the parts at their nominal dimension.

Based on the foregoing it can be appreciated that embodiments disclosedherein relate to a sensor testing system and method. In general, apressure rail having a top surface and a bottom surface and one or morepressure inlets to a pressure channel can be located within the pressurerail. The pressure channel can be drilled into the pressure rail. Aplurality of patch depressions can be formed into a plurality of sealingsurfaces on the top surface of the pressure rail upon which a patch ispositioned. A plurality of antenna blocks is generally disposed upon thepressure rail, wherein each antenna block thereof includes at least twoantennas. Two antennas can be connected to a respective antenna blockamong the plurality of antenna blocks utilizing a silicone adhesive.Each antenna block is respectively located on the pressure rail in orderto provide wireless data indicative of pressure and temperatureconditions associated with each patch among the plurality of patches.

Additionally, a plurality of BNC connectors can be respectivelyconnected to the plurality of antenna blocks, wherein each BNC connectorthereof is respectively connected to and protrudes from each antennablock thereof. Each sealing surface among the plurality of sealingsurfaces can be configured to contain a groove that retains a respectiveO-ring in place. The patch itself can comprise a SAW patch. Also, aplurality of cap screws can be provided for holding in place an antennablock among the plurality of antenna blocks and for sealing therespective O-ring against a respective antenna block among the pluralityof antenna blocks. The pressure rail therefore can generally function asa SAW tire pressure measurement patch wireless test rail. The SAW patchreacts to both temperatures and pressure while being interrogatedwireless as a fixed distance in order to collect test data indicative ofthe SAW patch.

The SAW Tire Pressure Measurement Patch Wireless test rail disclosedherein can be configured to permit five or more rubber patches to bepressurized up to 150 psi and to be heated up to 125 degrees Celsiuswhile the imbedded antenna interrogates the SAW patch. This allows theSAW patch to react both to temperature and pressure while beinginterrogated at a fixed distance to help collect final test data.

The test fixture can be configured using Ultem® material for the topantenna blocks and bottom pressure rail. Not that an example of Ultem®material that may be adapted for use in accordance with an embodiment isan Ultem® resin. An Ultem® resin is an amorphous thermoplasticpolyetherimide offering outstanding high heat resistance, high strength,modulus and broad chemical resistance. Ultem® is a trademark of theGeneral Electric Corporation. It can be appreciated of course that othertypes of amorphous thermoplastic polyetherimide materials may be adaptedfor use with embodiments and that the use of Ultem® material isdescribed herein for general illustrative purposes.

The pressure rail generally contains five or more (or less) individualdepressions cut into the top surface for placement and orientation ofthe SAW Patch. A pressure channel can be drilled through the center ofthe rail to help pressurize the SAW button face that is molded into thepatch. Each of the five locations contains a dovetail groove milled intothe sealing surface that holds a Silicon O-ring in place that also helpsretain the O-ring. The O-ring seals off against the Antenna block thatis held in place with four cap screws. The Antenna block contains twoantennas mounted inside to grooves held in place with RTV Siliconeadhesive. The two antennas can be wired to the BNC connector thatprotrudes out from the top of the Antenna block. The BNC connector canbe connected to a test system for monitoring and regulating thetemperature and pressure.

The embodiments and examples set forth herein are presented to bestexplain the present invention and its practical application and tothereby enable those skilled in the art to make and utilize theinvention. Those skilled in the art, however, will recognize that theforegoing description and examples have been presented for the purposeof illustration and example only. Other variations and modifications ofthe present invention will be apparent to those of skill in the art, andit is the intent of the appended claims that such variations andmodifications be covered.

The description as set forth is not intended to be exhaustive or tolimit the scope of the invention. Many modifications and variations arepossible in light of the above teaching without departing from the scopeof the following claims. It is contemplated that the use of the presentinvention can involve components having different characteristics. It isintended that the scope of the present invention be defined by theclaims appended hereto, giving full cognizance to equivalents in allrespects.

The embodiments of the invention in which an exclusive property or rightis claimed are defined as follows.

1. A sensor testing system, comprising: a pressure rail having a topsurface and a bottom surface and at least one pressure inlet to apressure channel located within said pressure rail; a plurality of patchdepressions formed into a plurality of sealing surfaces on said topsurface of said pressure rail upon which at least one patch among aplurality of patches is located; a plurality of antenna blocks disposedupon said pressure rail, wherein each antenna block thereof includes atleast two antennas and is respectively located on said pressure rail inorder to provide wireless data indicative of pressure and temperatureconditions associated with each patch among said plurality of patches.2. The system of claim 1 wherein each of said patches among saidplurality of patches comprises a SAW patch.
 3. The system of claim 1wherein said pressure rail comprises a SAW tire pressure measurementpatch wireless test rail.
 4. The system of claim 1 further comprising aplurality of BNC connectors respectively connected to said plurality ofantenna blocks, wherein each BNC connector thereof is respectivelyconnected to and protrudes from each antenna block thereof.
 5. Thesystem of claim 1 wherein each sealing surface among said plurality ofsealing surfaces contains a groove that retains a respective O-ring inplace.
 6. The system of claims 5 wherein said groove comprises adovetail groove.
 7. A SAW sensor testing system, comprising: a pressurerail having a top surface and a bottom surface and at least one pressureinlet to a pressure channel located within said pressure rail; aplurality of SAW patch depressions formed into a plurality of sealingsurfaces on said top surface of said pressure rail upon which at leastone SAW patch among a plurality of SAW patches is located; a pluralityof antenna blocks disposed upon said pressure rail, wherein each antennablock thereof includes at least two antennas and is respectively locatedon said pressure rail; and a plurality of BNC connectors respectivelyconnected to said plurality of antenna blocks, wherein each BNCconnector thereof is respectively connected to and protrudes from eachantenna block thereof in order to provide wireless data indicative ofpressure and temperature conditions associated with each SAW patch amongsaid plurality of SAW patches.
 8. The system of claim 7 wherein eachsealing surface among said plurality of sealing surfaces contains agroove that retains a respective O-ring in place.
 9. The system ofclaims 8 wherein said groove comprises a dovetail groove milled intosaid sealing surface for holding said respective O-ring in place. 10.The system of claim 8 wherein said respective O-ring comprises asilicone O-ring.
 11. The system of claim 7 wherein said pressure channelis drilled into said pressure rail.
 12. The system of claim 7 whereinsaid SAW patch reacts to both temperatures and pressure while beinginterrogated wireless as a fixed distance in order to collect test dataindicative of said SAW patch.
 13. The system of claim 9 furthercomprising a plurality of cap screws for holding in place an antennablock among said plurality of antenna blocks and for sealing saidrespective O-ring against a respective antenna block among saidplurality of antenna blocks.
 14. The system of 7 wherein said at leasttwo antennas are connected to a respective antenna block among saidplurality of antenna blocks utilizing a silicone adhesive.
 15. A sensortesting method, comprising the steps of: providing a pressure railhaving a top surface and a bottom surface and at least one pressureinlet to a pressure channel located within said pressure rail; forming aplurality of patch depressions into a plurality of sealing surfaces onsaid top surface of said pressure rail upon which at least one patchamong a plurality of patches is located; disposing a plurality ofantenna blocks upon said pressure rail, wherein each antenna blockthereof includes at least two antennas and is respectively located onsaid pressure rail; and thereafter generating from said plurality ofantenna blocks, wireless data indicative of pressure and temperatureconditions associated with each patch among said plurality of patches.16. The method of claim 15 further comprising the step of configuringeach of said patches among said plurality of patches to comprise a SAWpatch.
 17. The method of claim 15 further comprising the step ofconfiguring said pressure rail to comprise a SAW tire pressuremeasurement patch wireless test rail.
 18. The method of claim 15 furthercomprising the step of respectively connecting a plurality of BNCconnectors to said plurality of antenna blocks, wherein each BNCconnector thereof is respectively connected to and protrudes from eachantenna block thereof.
 19. The method of claim 15 further comprising thestep of configuring each sealing surface among said plurality of sealingsurfaces to form a groove that retains a respective O-ring in place. 20.The method of claims 19 wherein said groove comprises a dovetail groove.